Sexual Behavior, Condom Use, and Human Papillomavirus: Pooled Analysis of the IARC Human Papillomavirus Prevalence Surveys Salvatore Vaccarella, 1 Silvia Franceschi, 1 Rolando Herrero, 2 Nubia Mun ˜ oz, 3 Peter J.F. Snijders, 4 Gary M. Clifford, 1 Jennifer S. Smith, 5 Eduardo Lazcano-Ponce, 6 Sukhon Sukvirach, 7 Hai-Rim Shin, 8 Silvia de Sanjose ´, 9 Monica Molano, 3 Elena Matos, 10 Catterina Ferreccio, 11 Pham Thi Hoang Anh, 12 Jaiye O. Thomas, 13 Chris J.L.M. Meijer, 4 and IARC HPV Prevalence Surveys Study Group 1 International Agency for Research on Cancer, Lyon, France; 2 Proyecto Epidemiolo ´ gico Guanacaste, Fundacio ´ n INCIENSA, San Jose ´, Costa Rica; 3 Instituto Nacional de Cancerologı ´a, Bogota, Colombia; 4 VU University Medical Center, Amsterdam, the Netherlands; 5 Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina; 6 Instituto Nacional de Salud Pu ´ blica, Cuernavaca, Morelos, Mexico; 7 Research Division, National Cancer Institute, Bangkok, Thailand; 8 Research Institute, National Cancer Centre, Ilsan-gu Koyang, Kyonggi, Goyang, Korea; 9 Servei d’Epidemiologia i Registre del Ca `ncer Institut Catala ` d’Oncologia, L’Hospitalet del Llobregat, Barcelona, Spain; 10 Instituto de Oncologı ´a Angel H. Roffo, Universidad de Buenos Aires, Buenos Aires, Argentina; 11 Escuela de Medicina, Pontificia Universidad Cato ´ lica de Chile, Santiago, Chile; 12 National Cancer Institute, Hoankiem District, Hanoi, Vietnam; and 13 College of Medicine, University of Ibadan, Ibadan, Nigeria Abstract Human papillomavirus (HPV) is a sexually transmitted infection but it is unclear whether differences in transmission efficacy exist between individual HPV types. Information on sexual behavior was collected from 11 areas in four continents among population-based, age-stratified random samples of women of ages z15 years. HPV testing was done using PCR- based enzyme immunoassay. Unconditional logistic regres- sion was used to estimate odds ratios (OR) of being HPV positive and corresponding 95% confidence intervals (95% CI). Variables were analyzed categorically. When more than two groups were compared, floating confidence intervals were estimated by treating ORs as floating absolute risks. A total of 11,337 women (mean age, 41.9 years) were available. We confirmed that lifetime number of sexual partners is associated with HPV positivity (OR for z2 versus 1, 1.86; 95% CI, 1.63-2.11) but the association was not a linear one for HPV18, 31, and 33 (i.e., no clear increase for z3 versus 2 sexual partners). Women who had multiple-type infection and high- risk HPV type infection reported a statistically nonsignificant higher number of sexual partners than women who had single-type and low-risk type infections, respectively. Early age at sexual debut was not significantly related to HPV positivity. Husband’s extramarital sexual relationships were associated with an OR of 1.45 (95% CI, 1.24-1.70) for HPV positivity in their wives after adjustment for age and lifetime number of women’s sexual partners. We did not observe a significant association with condom use. Our study showed an effect of both women’s and their husbands’ sexual behavior on HPV positivity. Furthermore, it suggests some differences in the pattern of the association between sexual behavior and different HPV types. (Cancer Epidemiol Biomarkers Prev 2006;15(2):326 – 33) Introduction Human papillomavirus (HPV), the necessary cause of invasive cervical cancer and its precursor lesions (1), is sexually transmitted (2). Many studies (3-5) found a direct association of HPV infection with number of sexual partners, most notably with recent sexual partners (6-8). A few studies (8-10) suggested different risk profiles for high-risk and low-risk HPV types, but no study thus far has included a sufficient number of HPV-positive women to assess whether the strength of the association with sexual behavior varies between individual HPV types. Furthermore, a woman’s risk of contracting an HPV infection depends strongly on the sexual behavior of her male partners, and relatively little information is available on this issue (11). Finally, it is not clear whether age at sexual debut has any influence on the risk of being HPV positive later in life (3) and to what extent condom use might prevent HPV transmission (12). To further explore these issues, we present here an analysis of the sexual behavioral determinants of prevalent HPV infection from the International Agency for Research on Cancer (IARC) HPV Prevalence Surveys. Materials and Methods Contributing Studies and Data Collection. Similar proto- cols were developed for each of 11 areas in nine different countries and studies were carried out between 1993 and 2003. Population sampling methods have previously been described for the individual areas: Vietnam (13), Thailand (14), Korea (15), Mexico (16), Argentina (17), Chile (18), Colombia (19), Nigeria (20), and Spain (21). Vietnam and Thailand participat- ed with two studies each in different areas (Hanoi and Ho Chi Minh, Vietnam; Lampang and Songkla, Thailand). In Colom- bia, the study population was selected from women attending screening centers and family planning clinics. 326 Cancer Epidemiol Biomarkers Prev 2006;15(2). February 2006 Received 7/29/05; revised 10/27/05; accepted 12/22/05. Grant support: United Nations Development Programme/United Nations Population Fund/ WHO/World Bank Special Program of Research, Development, and Research Training in Human Reproduction, Department of Reproductive Health and Research, WHO, Switzerland (grant 94053A); WHO Technical Services Agreement A15312; and the Spanish Ministry of Health Instituto de Salud Carlos III (RCSP-09). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Note: P.T.H. Anh is currently at the PATH Canada Vietnam Office, Hanoi, Vietnam. Requests for reprints: Salvatore Vaccarella, IARC, 150 cours Albert Thomas, 69372 Lyon cedex 08, France. Phone: 33-4-72-73-80-97; Fax: 33-4-72-73-83-45. E-mail: vaccarella@iarc.fr Copyright D 2006 American Association for Cancer Research. doi:10.1158/1055-9965.EPI-05-0577 Downloaded from http://aacrjournals.org/cebp/article-pdf/15/2/326/2264783/326.pdf by guest on 15 March 2023